/**
 * Copyright (c) 2011, JFXtras
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the <organization> nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package jfxtras.scene.control;

/**
 * 
 * An interface that provides the data to a spinner
 * 
 * @author Tom Eugelink
 *
 * @param <T> the type of the spinner value (e.g. String)
 * @param <I> the type of the index being used by the spinner (e.g. Integer)
 */
public interface SpinnerXDataProvider<T, I>
{
	/**
	 * Calculate the previous index given the provided one.
	 * 
	 * @param index the current index, if null is specified return the first index (this only is possible if the data provider actually has a first index!)
	 * @return index, or null if there is no previous
	 */
	public I getPreviousIndex(I index);

	/**
	 * Calculate the next index given the provided one.
	 * 
	 * @param index the current index, if null is specified return the last index (this only is possible if the data provider actually has a last index!)
	 * @return index, or null if there is no previous
	 */
	public I getNextIndex(I index);
	
	/**
	 * Return the value for the specified index
	 * 
	 * @param index
	 * @return null is a valid value
	 */
	public T getValue(I index);
	
	/**
	 * Return the index for the specified value
	 * 
	 * @param value null is a valid value
	 * @return
	 */
	public I getIndex(T value);
	
	/**
	 * If the spinner is editable, this method is used to add a new value
	 * 
	 * @param value null is a valid value
	 * @return the index where this value is added, or null if it is not added 
	 */
	public I addValue(T value);
	
}
